The present invention thwarts aircraft hijackings and would have prevented the horrific tragedies of Sep. 11, 2001 at the World Trade Center, at the Pentagon and in the fields of Pennsylvania.
A significant advantage of this invention is that one embodiment may be retrofitted into virtually all existing commercial airliners immediately and at relatively low cost.
The present invention in one embodiment provides a relatively small microcode module installable in existing automatic flight controllers of commercial airliners. The modified microcode detects certain aircraft flight characteristics utilized only by terrorists, such as flying at low altitudes (for example, less than 8,000 feet altitude) at relatively high speeds (for example, more than 300 knots).
According to the present invention, if patterns of aircraft flight characteristics unique to terrorist hijackers are recognized by the modified microcode, the autopilot takes control of the aircraft and several significant steps follow. First, manual control of the aircraft is overriden temporarily. Secondly, the autopilot takes the aircraft into a controlled “parking” pattern, for example, the aircraft climbs to a given altitude (e.g. 17,000 feet) and flies in a circular pattern for a given amount of time (e.g. 15 minutes). Thirdly, contact is made by the presumably hijacked aircraft with ground controllers, and ground controllers are given an opportunity to either return the aircraft to cockpit control if no hijacking was in progress, or to decide to land the aircraft automatically if a hijacking is in progress. To return control of the aircraft an unlock code from the ground controllers must be entered into the autopilot, otherwise the microcode will cause the autopilot to autoland at the closest airport with sufficient runway and emergency facilities.
Most airline terrorist protection methods rely on detecting the hijacker and weapons before they board the airplane. Very little protection exists after the terrorist has seized control. The present invention detects the hijack in process and returns control of the airplane to ground based authorities. In its simplest implementation, the first embodiment of the invention is primarily a group of microcode subroutines that are added to the existing flight management computer system.
A second embodiment of the present invention provides a separate, microprocessor-based module which is placed in the aircraft. This embodiment has significant advantages over the first embodiment; for example, the module may be loaded with new microcode from a remote location.
The present invention also provides responses to aircraft in-flight emergencies other than hijackings. For example, the invention is capable of detecting in-flight emergencies such as fires, loss of cabin pressure, interruption of oxygen supply, etc., and notifying ground control as well as the onboard flight crew.
This invention is analogous to a fire extinguisher mounted on the wall and is only used in the event of a dire emergency. The invention interacts with the aircraft flight controls to a minimum extent and only in a sensed dire emergency.
A primary object of the invention is to provide a method and apparatus for thwarting attempts to hijack aircraft that may be quickly and inexpensively retrofitted into virtually all existing commercial airliners.
A further object of the invention is to provide a method and apparatus for detecting and responding to aircraft in-flight emergencies other than a hijacking.
A further object of the invention is to thwart an attempted hijacking by providing a method and apparatus for automatically sensing the presence of a hijack in process, taking automatic control of the aircraft, overriding attempts to manually control the aircraft and automatically causing the aircraft to fly in an approved emergency holding pattern.
Other objects and advantages of the invention will become apparent from the following description and the drawings wherein: